Khazars

The Khazars were a semi-nomadic Turkic people who formed a powerful khaganate in Eastern Europe from 650 to 969 AD. The Khazars originated in the Caucasus and came to build a large empire between the Dnieper River in the west and the Aral Sea in the east, adopting Judaism in the mid-8th century AD. The Khazars were ultimately invaded by Magyars and Pechenegs in the east and the Kievan Rus in the west during the 10th century, leading to their demise in 969 AD.

Origins
The Khazars originally lived in the Pontic Caspian Steppe on the northwestern shore of the Caspian Sea; they formed a section of the Hunnic tribal hierarchy, and they raided and plundered throughout the south Caucasus century. By the mid-6th century AD, they had subjugated the tribes north of the Caucasus Mountains, but the Gokturks continued to be the main power in the steppe, bringing the Khazars under their rule as a leading portion of the Western Turkic Khaganate's military strength. In 630, the Western Khaganate dissolved following Tong Yabghu Qaghan's death, and the rise of Islam in the Middle East and the northern advance of the Rashidun armies by 640 filled the power vacuum. The Muslim armies threatened to invade through the mountain passes, and, in 642, Muslim raiders reached Derbent between the Caucasus and the Caspian. For the next 8 years, the Muslims slowly pushed past Derbent and towards the Khazar capital at Balanjar, and a Byzantine-Khazar army was defeated in Armenia. In 652, an Arab army was sent to attack Balanjar, but they were repelled with heavy losses.

Arab-Khazar Wars
As the Muslims refocused on their war with the Byzantines, the Khazars expanded to the north during the 650s and 660s, asserting their hegemony over the Magyars and Bulgars; two columns of Bulgar refugees made their way to the Danube and Volga, forming the Bulgarians and Volga Bulgars, respectively. The Khazars became a khaganate with a complex administrative system, and they raided the Caucasus several times; by 692, the Umayyad lord of Armenia set about establishing several forts south of the Caucasus, but, in 721, the Khazars took the offensive and instigated a 15-year war in Armenia. The Khazars under Barjik invaded Muslim lands in Azerbaijan in 730, and, in the Battle of Marj Ardabil, they destroyed a 25,000-strong Arab army under al-Jarrah ibn Abdallah and killed their commander. However, the Khazars scattered throughout the area in search of loot and plunder, allowing for the Arabs to counterattack and drive them back into the Caucasus. In 750, the less-expansionist Abbasids took power, ending the Arab-Khazar Wars.

Conversion to Judaism
Around 740, the Khazars decided to abandon their Tengri beliefs in favor of a powerful monotheistic faith, which they believed would make them a legitimate power in the eyes of the Christian West and the Islamic East. Rather than subordinate themselves to either the Christian emperor or the Muslim caliph, the Khazar ruling class converted to Judaism, the third major monotheistic faith; the faith had been introduced to the region by Hellenized Jews (many of whom had fled persecution at the hands of Heraclius and Leo III). Jewish refugees from the Byzantine and Muslim lands arrived in the Khazar lands and created a cosmopolitan outlook of tolerance in the Khazar capital of Atil, and Jewish missionary refugees brought Byzantine arts, crafts, and agricultural and trade methods to the Khazars, who adopted the neutral faith as their own. The Khazars began to issue Jewish-themed Moses coins, and they became known as traders in the 8th and 9th centuries. Khazar merchants made their way to Volga Bulgaria, Khwarezm, China, India, and Sweden to export their goods, and traders from other lands settled in Atil to sell their own goods to the Khazars. By the start of the 10th century, Magyars and Pechenegs began to rampage through their lands, while the Varangians of Kievan Rus cut off their dominion west of the Dnieper River. Starting in 900, the Khazars began a series of wars with the Rus, and, in the late 960s, Sviatoslav I of Kiev sailed down the Volga River and sacked Atil, dismantling the Khazar state; his son Vladimir the Great asserted Rus authority over former Khazar territories such as Samandar, burning its revered gardens. The Kievan state inherited governmental framework and military organization from the Khazars, and Jewish Khazar refugees may have gone on to form a large portion of the Ashkenazi Jews of Eastern Europe.